Yellow rain in Orange County today
The water I collected in my rain barrel today is yellow, and some yellow powder seemed to be floating on the surface. I saw the same thing in some rain that collected on the lid of a barrel in my back yard. The only thing I can think of is it must be pollen, either that was washed out of the air by the rain or was already on my roof and the barrel lid.
I remember when I was working in Mississippi next to a pine forest the concrete parking lot would be covered in pollen, so maybe this is the same thing but there aren't any forests around here.